1. Field of the Invention
The present invention relates to a control arrangement for influencing individual threads in a thread sheet, in particular, for warp knitting machines comprising a bar extending in the longitudinal direction having provided therein, stroke elements moveable in the stroke direction and a carrier extending in the longitudinal direction driveable to and fro in the stroke direction which is provided with adjacently ordered piezoelectric transducers. One end of said transducers being connected to the carrier and the other, free end, in dependence upon electrical control signals will either take up a first position, or a second position displaced in the longitudinal direction. The arrangement further comprises entrainment means which are connected to the free end of the transducers. The entrainment means (a) in the first position can move appropriate stroke elements in the stroke direction by contacting a counterstop of the stroke element, and (b) in the second position can leave the stroke element uninfluenced.
2. Description of Related Art
In a known stroke control arrangement of this type (DE 195 14 995 A1, FIGS. 8 through 11) the strip-formed piezoelectric transducers are provided as extensions of the corresponding stroke elements. The entrainment means are attached to flanges attached to and extending beyond both sides of the free ends of the transducers which, in the first position work together with a front facing step of the stroke element and in the second position are so bent that they lie next to the appropriate stroke element, wherein the transducer enters into an aperture in the stroke element. Since the transducers are attached to the carrier and are constantly moved backwards and forwards therewith, it is not necessary to provide sensitive pawls controlled by fixed transducers to the stroke elements (DE 195 14 995 A1, FIGS. 1 through 7). However, certain deficiencies in the transducers must be taken into account.
A purpose of the present invention is to provide a stroke control arrangement of the sort described hereinabove which better addresses the requirements of the art.
This task is preferably served thereby that the entrainment means are provided in the transverse direction adjacent to the transducers and at one end thereof are supported in a construction unit rigidly affixed to the carrier and whose other end carries the entrainment means.